RSM3203 - Compact 1A CoolModule for Space-Constrained Designs

Compact 1A CoolModule™ for Space-Constrained Designs

The RSM3203 1A CoolModule™ is a fully integrated DC/DC power module that combines a high-efficiency synchronous buck converter and inductor in a compact 2.0mm × 2.5mm × 1.1mm LGA package. Designed for space-constrained applications, the integrated-inductor architecture minimizes external components, simplifies PCB layout, and delivers efficient, high-density point-of-load power.

Operating from a 2.4V to 5.5V input voltage range, the module supports switching frequencies up to 4MHz, enabling smaller external components and reduced overall solution size. Automatic PFM/PWM operation provides high efficiency across varying load conditions, while the RSM3203F offers Forced PWM operation for noise-sensitive applications.

Ideal for optical modules, portable electronics, IoT devices, and industrial embedded systems, the RSM3203 1A CoolModule™ combines compact integration, flexible operation, and built-in protection to simplify power supply development.

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CoolModule™ Integration Simplifies Power Design

By integrating the synchronous buck power stage and inductor into a single package, Reed Semiconductor’s CoolModule™ technology eliminates one of the largest external components required by a traditional buck converter. The result is a smaller solution footprint, fewer components, and simplified placement and routing.

Integrated Inductor Reduces PCB Area

The integrated inductor minimizes external component count and reduces PCB area compared with discrete buck converter implementations, making the RSM3203 1A CoolModule well suited for designs where board space is at a premium.

High-Density Power Solution

With switching frequencies up to 4MHz, designers can use smaller external capacitors while maintaining fast transient response and high efficiency. Combined with its 2.0mm × 2.5mm footprint, the RSM3203 provides a highly integrated point-of-load solution for compact electronic systems.

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Flexible Performance Across a Wide Range of Applications

Designed for battery-powered and regulated power rails, the RSM3203 CoolModule™ combines a wide input range with multiple operating modes and factory-trimmed output voltage options.

Wide Input Voltage Range

Supporting 2.4V to 5.5V input voltages, the RSM3203 CoolModule is compatible with USB-powered devices, single-cell lithium-ion batteries, and regulated intermediate power rails.

Automatic or Forced PWM Operation

Designers can select the operating mode that best fits their application:

• Automatic PFM/PWM mode for high efficiency across a wide load range (RSM3203A–RSM3203E)
• Forced PWM mode for predictable switching behavior in noise-sensitive applications (RSM3203F)

Factory-Trimmed Output Voltage Options

Five fixed output voltage options—0.6V, 1.2V, 1.8V, 2.5V, and 3.3V—simplify power supply design while minimizing external components.

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Integrated Features Improve System Reliability

The RSM3203 integrates monitoring and protection functions that simplify implementation and help protect the power supply and downstream circuitry.

Integrated System Functions

• Power-good (PG) output
• Output discharge function
• Up to 1A continuous output current
• ±1% output voltage accuracy

Built-In Protection

• Cycle-by-cycle overcurrent protection
• Short-circuit protection
• Thermal shutdown

These integrated functions reduce the need for additional supervisory circuitry while improving overall system robustness.

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Compact CoolModule™ Packaging

The 2.0mm × 2.5mm × 1.1mm LGA package integrates the power converter and inductor into a compact power solution that significantly reduces PCB area compared with traditional discrete implementations.

By minimizing component count and simplifying layout, the RSM3203 CoolModule™ helps accelerate development while improving design and manufacturing consistency.

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Part of the CoolModule™ Power Family

The RSM3203 1A CoolModule is a member of Reed Semiconductor’s CoolModule™ family, a scalable portfolio of integrated-inductor DC/DC power modules. The RSM3203, RSM3204, and RSM3205 share a compact package architecture while providing different output-current capabilities.

The common architecture allows designers to scale output current with minimal PCB redesign, simplifying product development and inventory management.

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Explore Reed CoolModule™ Power Solutions

The RSM3203 1A CoolModule™ is part of Reed Semiconductor’s growing portfolio of integrated DC/DC power solutions designed to simplify power supply development while maximizing power density. For higher-current requirements, designers can move to the RSM3204 2A CoolModule™ or RSM3205 3A CoolModule™ while maintaining the advantages of an integrated-inductor architecture.